The invention concerns more particularly, but not exclusively, a light of the fog type.
The patents FR-A-2 774 150 or EP 933 585 show a light of this type with reflectors whose surface is determined so as to provide the cutoff beam, that is to say the light rays of the reflected beam are situated essentially below a cutoff line which may be horizontal, or which may be formed by a broken line in the case of a dipped headlight. The light source used is fairly powerful so that the fraction of the light emitted towards the rear in the direction of the reflector suffices to produce the required light beam. In order to avoid the light emitted towards the front by the light source creating dazzling by direct observation, a shield is generally provided situated in front of the light source. Part of the light flux is therefore used for the lighting beam, which does not prevent satisfying the photometric pattern conditions for the light beam in the case of a high-power source.
The heat given off by such a high-power light source on the one hand requires closing the housing of the light with a glass cover in order to resist the high temperature and on the other hand imposes a relatively great distance between the light source and the glass, which gives rise to a significant size of the housing in terms of depth.
The purpose of the invention is in particular to provide a light beam of the type defined above which makes it possible to obtain a satisfactory light beam with a light source of relatively low power, and which is relatively compact. It is also wished for the heating due to the light source to be sufficiently small to make it possible to use a cover made from plastics material with a reduced space requirement.
Another aim of the invention is to provide a light that allows simple and rapid adjustment of the cutoff of the beam in the vertical direction.